Construction of Bi2O2CO3/Ti3C2 heterojunctions for enhancing the visible-light photocatalytic activity of tetracycline degradation

[Display omitted] •The composites Bi2O2CO3/Ti3C2 were prepared by a simple hydrothermal method.•The formation of Bi2O2CO3/Ti3C2 helped the separation of electrons and holes.•The photocatalytic degradation effects of several single antibiotics and mixed antibiotics were explored.•The pathway and catalytic mechanism of Bi2O2CO3/Ti3C2 degradation of TC were explained. Bi2O2CO3 (BOC) was successfully loaded on a highly conductive Ti3C2 surface by the hydrothermal method, forming a unique BOC/Ti3C2 heterostructure. The use of advanced characterization methods reveals the composition, morphology and photoelectric properties of the material. The results show that the interface formed by close contact between BOC and Ti3C2 provides an effective channel for charge transfer between the two. Importantly, the photocatalytic degradation efficiency of BOC/Ti3C2 for tetracycline (TC) is ~80%, which is significantly higher than the degradation efficiency of pure BOC and pure Ti3C2 for TC. In addition, BOC/Ti3C2 still has high catalytic activity in the degradation of complex mixed antibiotics. This is because BOC and Ti3C2 have large specific surface areas, high light absorption capacity and efficient carrier separation after recombination. At the same time, the detected superoxide radicals (O2−) and holes (h+) are the main active substances. The degradation pathway and catalytic mechanism of the photocatalytic degradation of TC by BOC/Ti3C2 are further explained. This research designed and developed a BOC/Ti3C2 composite material for the photocatalytic degradation of tetracycline and mixed antibiotic wastewater, providing experimental methods and ideas for actual wastewater treatment.